Abstract: An MRI apparatus includes an imaging means being provided with a means for generating magnetic fields respectively of a static magnetic field, a gradient magnetic field, and an RF magnetic field, and a means for receiving an echo signal generated from a subject, the imaging means being for measuring echo data associated with at least one measurement trajectory in k-space, while varying angles with respect to a coordinate axis in the k-space of the measurement trajectory, so as to collect at least one measured data for each of the angles; and an image reconstruction means for rearranging the measured data in the k-space and reconstructing an image; wherein, the image reconstruction means calculates a phase for correction based on standard data selected from the measured data for each of the angles, prior to rearranging the measured data in the k-space, and performs a phase correction as to the measured data, by using the phase for correction being calculated.

Abstract: Plural blood vessels different in blood flow velocity are depicted with high image quality in blood vessel imaging using PC-MRA method. For this purpose, the present invention performs a measurement of an echo signal based on application of a positive-polarity flow encode pulse and a measurement of an echo signal based on application of a negative-polarity flow encode pulse on an examinee with each of plural phase encodes while varying the flow encode, and a blood vessel image of the examinee is reconstructed by using the plural echo signals having different flow encode absolute values.

Abstract: An RF receiving means, which comprise respective at least three RF receiving coils (203, 201 (or 202), 204), (205, 202 (or 201), 206), (207, 201 (or 202), 208) disposed in at least two orthogonal directions (x, y, z), are set to a patient 209, any one direction (x) of the two directions is set as a phase encoding direction, magnetic resonance signals are measured by executing a pulse sequence while thinning phase encoding steps, and the aliasing of an image is eliminated by an arithmetic operation executed using the magnetic resonance signals measured by at least the three RF receiving coils (205, 202 (or 201), 206) disposed in the thus set phase encoding direction and using the sensitivity distributions of the respective RF receiving coils.

Abstract: The present invention provides a magnetic resonance imaging system capable of performing spectrum measurement even when a magnetic resonant frequency changes during MRS measurement. A time-varying rate of a water magnetic resonant frequency is measured in advance before the MRS measurement. The amount of change in water magnetic resonant frequency during the MRS measurement is predicted from the measured time-varying rate. With the predicted value as the reference, a transmission frequency of an RF magnetic field irradiated in a signal suppression pulse sequence, a transmission frequency of an RF magnetic field for excitation and inversion and a received frequency at the detection of a magnetic resonance signal in a sequence of the MRS measurement are respectively set. A high-precision spectrum measurement is hence enabled.

Abstract: An MRI apparatus includes an imaging means being provided with a means for generating magnetic fields respectively of a static magnetic field, a gradient magnetic field, and an RF magnetic field, and a means for receiving an echo signal generated from a subject, the imaging means being for measuring echo data associated with at least one measurement trajectory in k-space, while varying angles with respect to a coordinate axis in the k-space of the measurement trajectory, so as to collect at least one measured data for each of the angles; and an image reconstruction means for rearranging the measured data in the k-space and reconstructing an image; wherein, the image reconstruction means calculates a phase for correction based on standard data selected from the measured data for each of the angles, prior to rearranging the measured data in the k-space, and performs a phase correction as to the measured data, by using the phase for correction being calculated.

Abstract: A magnetic resonance imaging apparatus comprises object placing means for placing an object in an imaging space, translating means for translating the object in a given direction by translating the object placing means in the given direction continuously or step-wise, magnetic field generating means for exciting the desired region of the object by generating a static magnetic field, a gradient magnetic field in the imaging space, and a high-frequency magnetic field in the imaging space, signal detecting means for detecting a magnetic resonance signal from the object, and control unit for controlling the translating means, magnetic field generating means and the signal detecting means, and translating the object continuously or stepwise to a predetermined position at a predetermined speed so as to capture a magnetic resonance image of the object.

Abstract: In an imaging according to the step moving method, a slice imaging condition with respect to each station is optimized, thereby enabling an efficient imaging. A controller of an MRI apparatus displays positioning frames 601 to 606, and operation handles 607 and 608 thereof, in order to set a slice imaging condition at every various positions (stations) of a table on which a test object is mounted. By manipulating the positioning frames and the operation handles via I/O unit, the slice imaging condition is set. According to this slice imaging condition, imaging at each station position of the table is executed.

Abstract: An RF coil is provided with a hollow-shaped outer conductive element and strip-shaped conductive elements disposed along the outer conductive element in the axial direction. The strip-shaped conductive elements are disposed with uneven intervals to secure an internal space at a position where the strip-shaped conductive elements are not disposed. In order to obtain uniform sensitivity at the center section of the RF coil, the strip-shaped conductive elements and the outer conductive element are electrically connected via capacitors of which capacitances are adjusted so that a magnetic field component perpendicular to the center axis should be generated at a desired resonance frequency, and the strip-shaped conductive elements are axisymmetrically disposed with respect to the center axis of the outer conductive element. As a result, a comfortable examination space in a tunnel type MRI apparatus is achieved without increasing the manufacturing cost of the MRI apparatus.

Abstract: A magnetic resonance imaging apparatus comprising static magnetic field generating means for generating a static magnetic field in an imaging space, measuring means for generating a high-frequency magnetic field and a gradient magnetic field in the imaging space and measuring a nuclear magnetic resonance signal generated from an object to be examined placed in the imaging space, signal processing means for reconstructing a magnetic resonance image according to the nuclear magnetic resonance signal, control means for controlling the measuring means and the signal processing means, and display means for displaying the reconstructed magnetic resonance image obtained by the signal processing means.

Abstract: A magnetic resonance imaging apparatus comprises object placing means for placing an object in an imaging space, translating means for translating the object in a given direction by translating the object placing means in the given direction continuously or step-wise, magnetic field generating means for exciting the desired region of the object by generating a static magnetic field, a gradient magnetic field in the imaging space, and a high-frequency magnetic field in the imaging space, signal detecting means for detecting a magnetic resonance signal from the object, and control unit for controlling the translating means, magnetic field generating means and the signal detecting means, and translating the object continuously or stepwise to a predetermined position at a predetermined speed so as to capture a magnetic resonance image of the object.

Abstract: A magnetic resonance imaging apparatus comprises static magnetic field generating means for generating a static magnetic field in an imaging space, a gradient magnetic field generating means for generating a gradient magnetic field in the imaging space, high-frequency magnetic field generating means for generating a high-frequency magnetic field so as to induce nuclear magnetic resonance in a subject placed in the imaging space, signal receiving means for detecting a nuclear magnetic resonance signal from the subject, signal processing means for reconstructing an image by using the detected nuclear magnetic resonance signal, display means for displaying the image, a table for placing the subject thereon to dispose the subject in the imaging means, and table moving means for moving the table on which the subject is placed. While moving the portions to be imaged of the subject continuously or stepwise in the imaging space and disposing the subject, a whole-body image of a large region of the subject is created.

Abstract: In a non-cartesian sampling method, in order to reduce an artifact on an image caused by an error of a gradient magnetic field, data for correcting the error caused by the gradient magnetic field are obtained when data used for image reconstruction are obtained, and the data used for the image reconstruction are corrected by using the obtained data for the correction. In order to obtain the data for correcting the error, a block having plural parallel echo signals is measured.

Abstract: In order to stably obtain an even fat-suppressed image without reduction of an imaging efficiency and without being affected by unevenness of irradiation magnetic field of an RF pulse, when an imaging sequence having a first sequence part for suppressing a signal from a desired component of an examinee by applying a CHESS pulse and a second sequence part for measuring an echo signal from the examinee is repeated, the flip angle of the CHESS pulse is changed at plural times. In the case of multi-slice imaging, the flip angle of the CHESS pulse is changed in at lest two slice imaging.

Abstract: An MRI apparatus includes an imaging means being provided with a means for generating magnetic fields respectively of a static magnetic field, a gradient magnetic field, and an RF magnetic field, and a means for receiving an echo signal generated from a subject, the imaging means being for measuring echo data associated with at least one measurement trajectory in k-space, while varying angles with respect to a coordinate axis in the k-space of the measurement trajectory, so as to collect at least one measured data for each of the angles; and an image reconstruction means for rearranging the measured data in the k-space and reconstructing an image; wherein, the image reconstruction means calculates a phase for correction based on standard data selected from the measured data for each of the angles, prior to rearranging the measured data in the k-space, and performs a phase correction as to the measured data, by using the phase for correction being calculated.

Abstract: When multiple types of imaging are performed while moving a table on which a subject to be examined is placed, an imaging efficiency is improved and a high-quality image is obtained within a short time. Therefore, within a predetermined time interval such as an identical period of a periodic living body motion, a predetermined number of echo signals from each of the multiple types of imaging sequences are acquired and the table on which the subject to be examined is placed is moved. Along with the movement of the table, data items within the same range in the Ky-direction as to each of the imaging sequences are acquired, the moving speed of the table is controlled in such a manner that the acquired data items become continuous in the x-direction, and images are reconstructed based on the data items obtained respectively from the imaging sequences.

Abstract: When performing imaging in synchronization with a biological movement of an examinee by using a pulse sequence applying a pre-saturation pulse, it is possible to reduce irregularities of echo signal intensity and artifact on the image generated by the irregularities. Especially, it is possible to prevent artifact attributed to blood in the ventricle when performing delay contrast imaging. For this, before measuring the echo signal, an IR pulse or the like for adjusting magnetization to a desired state is applied so as to suppress irregularities of the echo signal intensity and prevent artifact.

Abstract: An MRI apparatus capable of performing a high-speed operation for removing aliasing from the data measured by non-Cartesian imaging in a real space with a small amount of operation is provided. Non-Cartesian data sampling is performed by thinning the number of data by using multiple receiver coils having different sensitivity distribution from each other. Image reconstruction means creates orthogonal data by gridding non-orthogonal data obtained by each receiver coil on a grid having an equal spatial resolution to and a narrower field of view than a target image, subjects it to Fourier transform and creates the first image data containing aliasing components. The second image data is created by using the first image data created for each receiver coil and a sensitivity distribution of each receiver coil.

Abstract: A magnetic resonance imaging device includes magnetic field generating means and control means for controlling receiving means according to a predetermined pulse sequence, the predetermined pulse sequence including an unnecessary material suppressing sequence unit for canceling a signal from an unnecessary material which is not a measurement target and a main imaging sequence unit for measuring a nuclear magnetic resonance signal used to create an image of an examinee. The unnecessary material suppressing sequence unit generates at least two or more high frequency magnetic field pulses so that the longitudinal magnetization of the unnecessary material is made spatially uniform in the imaging space under application of a first high frequency magnetic field pulse in the main imaging sequence unit.

Abstract: In performing the moving table imaging, an MRI apparatus and a method thereof are provided, which minimizes image degradation and reduces imaging time. When an image of a wide range of a test object is taken, the imaging is repeated while changing the gradient magnetic field intensity in a phase-encode direction, as well as changing the size of field of view FOV in the readout direction by changing the readout gradient magnetic field intensity in reading out the data, according to the phase-encode amount. In a part where the FOV is expanded, data acquisition frequency is lowered, and consequently, the total imaging time is reduced. The data sampling time may be changed along with the change of the FOV, and therefore, a process for achieving a unique matrix size in the readout direction is rendered unnecessary, and a spatial resolution can be maintained.

Abstract: A control means controls an imaging means for taking an image of a test object by a magnetic resonance, the test object being placed in an imaging space, and a transfer means that moves the test object, and on the basis of a difference (moving distance) between a position of the transfer means at the time of receiving a command of pausing the imaging and a position of the transfer means at the time of resuming the imaging, the control means controls the position of the transfer means or the position for imaging at the time of resuming, in such a manner that missing of data 503 caused by the difference can be compensated. With this configuration, it is possible to provide an MRI apparatus that is provided with an imaging pause function, and even when the pause function is activated, there is data consistency between the data before the pausing and the data after the resuming, thereby obtaining a high quality image.